You can frag a bubble easily. You need a dremmel and a very thin blade, or use a jewerly saw or a tile saw. Make sure you are dripping salt water on the coral as you begin the cut. Try to cut it down the middle with as clean of a cut as possible. Wear eye protection b/c you will get alot of slimy stuff on you. Dont be afraid to cut it, as long as its in good health to begin with, your success rate should be around 90% or better. If you need more detailed instruction or help just let me know.